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package com.icee.myth.utils;

/**
 *
 * @author yangyi
 */
public class Escape {

    public static String escape(String src){
        int i;
        char j;
        StringBuffer tmp = new StringBuffer();
        tmp.ensureCapacity(src.length()*6);
        for (i = 0; i < src.length(); i++) {
            j = src.charAt(i);
            if(Character.isDigit(j) || Character.isLowerCase(j) || Character.isUpperCase(j)){
                tmp.append(j);
            } else{
                if(j < 256){
                    tmp.append("%");
                    if(j < 16){
                        tmp.append("0");
                    }
                    tmp.append(Integer.toString(j,16));
                } else {
                    tmp.append("%u");
                    tmp.append(Integer.toString(j,16));
                }
            }
        }
        return tmp.toString();
    }
    public static String unescape(String src){
        StringBuffer tmp = new StringBuffer();
        tmp.ensureCapacity(src.length());
        int lastPos = 0, pos = 0;
        char ch;
        while (lastPos < src.length()) {
            pos = src.indexOf("%", lastPos);
            if(pos == lastPos){
                if (src.charAt(pos+1) == 'u') {
                    ch = (char)Integer.parseInt(src.substring(pos+2,pos+6),16);
                    tmp.append(ch);
                    lastPos = pos + 6;
                } else {
                    ch = (char)Integer.parseInt(src.substring(pos+1,pos+3),16);
                    tmp.append(ch);
                    lastPos = pos + 3;
                }
            } else {
                if (pos == -1){
                    tmp.append(src.substring(lastPos));
                    lastPos = src.length();
                } else {
                    tmp.append(src.substring(lastPos, pos));
                    lastPos = pos;
                }
            }
        }
        return tmp.toString();
    }
}
